井上 尚三

This paper reports on two types of fabrication methods for Si nanowires (NWs) using focused ion beam (FIB), photolithography, TMAH anisotropic wet-etching, and sacrificial oxidation. Type A specimens made from silicon-on-nothing (SON) membranes are produced by FIB system's probe manipulation and film deposition functions. The mean Young's modulus of FIB-fabricated NWs evaluated by tensile testing in SEM using electrostatic actuated MEMS device is 129 GPa. After vacuum annealing, the Young's modulus is increased to 168 GPa. Type B specimens are produced by wire-thinning technique using sacrificial oxidation and oxide film removal. We succeeded in making freestanding bridge Si NW with the width of 76 nm.

Focused ion beam (FIB) is one of strong nanofabrication tools for Si and its related devices. In this study, To produce ultra-fine Si nanowires less than 50nm, we propose a new nanostructure fabrication technique using FIB and anisotropic etching. Si nanowires of several tens of nm could be formed, and it was found that the nanowires consisted of Ga ion doped amorphous Si. Uniaxial tensile test of the nanowires was performed to directly measure the Young's modulus and fracture strength.